The present invention relates in general to scraper-chain conveyors as used in mineral mining and more particularly to the fixing of attachments to the side walls of the channel sections or pans of the conveyor.
It is well known to utilize threaded members to fix various attachments such as spill plates, rails, hoods, channels and guides to the side walls of the pans of a scraper-chain conveyor. The individual pans of the conveyor normally have sigma-shaped side walls and a floor plate therebetween. A central deep V-shaped groove is present in the exteriors of the side walls and holders for locating bolts are fitted into the grooves to enable the attachments to be secured. It is also known to provide rectangular holes in the upper flanges of the side walls to receive the heads of bolts (German Gebrauchmuster No. 19151116) and to provide vertical recesses at the upper regions of the side walls where the upper flanges merge with upstanding webs leading to the V-shaped grooves (German Patent Specification No. 1286489). In the latter case, the recesses have a trapezoidal shape and again receive the heads of conventional bolts. Bolts with heads of rectangular shape are employed and when fitted these heads only partly fill the recesses or holes. If the recesses extend through the upper webs of the side walls there is a danger that material, especially fine coal dust, can find its way into the recesses. The circulating scraper-chain assembly also has to pass alongside the open recesses and if the bolts become loose there is a danger that the assembly will be impeded and damage can occur. Furthermore the smooth profile of the side walls of the pans is interrupted by the recesses or holes and this is disadvantageous especially where a winning machine is moved back and forth alongside the side walls.
It is also known to reinforce the side walls of the pans of a conveyor by welding bars or strips to the exterior (German Patent Specification Nos. 2516082 and 2531861). These bars or strips can themselves be provided with recesses open from above into which the heads of bolts can be received.
A general object of the present invention is to provide an improved method of fixing attachments to the side walls of the pans of a scraper-chain conveyor.